Machine for reboring cylinders.



0. W. NELSON.

MACHINE FOR REBORING CYLINDERS.

AF'PHCATION FILED MAR-28,1918.

Patented Feb. lb, 1915).

3 SHEETS SHEE] l.

O. W. NELSON.

MACHFNE FOR REBORING CYLINDERS.

AF'PHCATION Fl-LED MAR 28, 19l8.

(J. W. NELSON.

MACHINE FOR HEBORING CYLINDERS.

AIPLICATION FILED MAh. 21:. 11112:.

1,295,052., iat'entml Feb. 1b, 1912,).

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Specification of Letters Patent.

Patented Feb. 18, 1919.

Application filed March 28, 1918. Serial No. 225,240.

"exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to new and useful improvements in the provision of machines for reboring the cylinders of explosive engines and the like, and of that portable type wherein there is provided an attaching member adapted for securement .to the end of the cylinder'and carrying a feed shaft on which is mounted a cutter heal movable into the cylinder. The present invention is an improvement of the machines illustrated in- Patents No. 1,146,665, dated July 13,

1915, and No. 1,209,513, dated December 19, 1916, issued jointly to Adolph Storm and Edward C. OHair.

It is in general the object of the invention to improvethe structure of machines of this character, both with respect to the readiness and economy with which their various pa rts may be manufactured and assembled, and -.with respect to the efficiency and durability of the machines in use.

A machine of the present character comprises a cutter head having means for centering it in an engine cylinder and a support engageable with the end of the cylinder, to be.clamped between the cylinder and a plate carrying the feed shaft for the cutter head. An important and more specific object is to avoid the provision of ac- 1 in the cylinder and having engagement with the cutter head in such manner that the bearing faces of said means and the cutter head are protected from the cylinder cuttings. A still further object resides in the provision of means for affordingv a bearing for des in the provision,

the cutting mechanism within the cylinder,

in addition to the bearing afforded by the centering means which moves in advance of the cutter blades, whereby, in the instance of a cylinder open at both ends or having a combustion enlargement at one end, the cutter head may be properl supported upon movement of its forwar bearing means past the end of the cylinder or into the cornbustion enlargement. It is more particularly an object to efl'ect this bearing by the provision of an auxiliary cutter head attachable to the main cutter head for carrying the cutter blades, whereby said main cutter head may be utilized to carr guide members engageable with the .cylin er. It is further an object to utilize these guide members also as a means for finishing the surface cut by the machine.

With the above and other objects and advantages 1n view, the invention resides more particularly in the novel combination, for

mation and arrangement of parts herein after described and pended claims.

In the accompanying drawings Figure 1 is a vertical sectional view through my improved reboring machine attached to the end of an engine cylinder in initial position for effecting, the boring operation. a

Fig. 9 is a transverse sectional view there through on the line 2-2 of Fig.1.

Fig. 3 is a perspective disassembled. view of the centering bearing ft the cutter head.

Fig. 4' is a detail sectional view on the line M of Fig. 1. a

Fig. 5 is a vertical sectional view through pointed out in the apthe boring machine provided with an extension cutterhead, and associated with an engine cylinder of that type having one end enlarged to form a combustion chamber.

Fig. 6 is a transverse sectional View on the line 66 fiFig. 5.

Fig. 7 is a "perspective view of a combined guide and finishing member adapted for use in connection with the extension cutter head.

Fig. 8 is a pers ective view of the auxiliary cutter head lock.

Referring nownlore particularly to the accompanying drawings, 5 designates the cylinder of an explosive engine, having the usual apertured attaching flange 6 extending laterally from its open end, As in the aforementioned patents, the reborlng ma-.'

- chine includes a tubular supporting member 7 having its internal diameter slightly greater than the diameter of the cylinder and adapted to seat against the cylinder flange 6 at its inner end and having its outer end engageable in an annular rabbet 8 of a bearing plate 9 having a central llb portion 10 in which is engaged a threaded bushing 11 for the feed shaft 12' of the machine, which shaft is rotated to operate the machine by suitable means engaged with its squared outer end. The structure described is clamped to the cylinder flange by bolts 13 passed through the apertures of said flange and through slots 14 in the ends of a yoke plate 15, the central portion of which is disposed loosely about the hub 10 and bears against the plate 9.

My improved cutter head differs considerably from the cutter heads of the aforementioned patents and comprises a body block 16 of generally cylindrical shape and having an annular boss 17 on one end through which and through the remainder of the block passes a threaded bore 18. The inneriend of the feed shaft is reduced and threaded into the boss whereby the cutter head is secured to the shaft. Also threaded in the bore is an expanding plug 19 having one end reduced at 20 in frusto-conical shape to engage the beveled inner ends of cutter blades 21 mounted in radial slots 22 in that portion of the head remote from the feed shaft. The end portion of the cutter head block is cut away to define an annular boss or hub 23 and to expose the outer sides of the slots 22, whereby the blades may be clamped in the slots by an annular plate 24 formed of suitable bearing metal for a purpose hereinafter described and fitted on the hub 23 and provided with threaded openings adapted to register with openings 25 extended through the head longitudinally of its axis for the reception of clamping bolts 26. Thus by tightening or loosening the bolts 26, While still retaining the parts of the head in assembled relation, the cutter blades may be clamped in place or released for adjustment.

To provide a bearing means for holding the cutter head centered within the cylinder, which means has its parts so disposed as to protect its bearing faces from the cuttings of the blades, an annular plate 27 is provided having its inner peripheral edge beveled to form a frusto-conical bearing face for engagement with the corresponding face of a bearing plug 28 having a reduced portion threaded in the bore of the cutter head block 16. An annular ridge 29 is formed on the inner face of the plate and provides a bearing face disposed in a plane at right angles to the axis of the cutter head and engageable with the outer face of the plate 24, which thus serves the double function of a the plate.

bearing member and blade clamping means. The outer peripheral edge of the plate 27 is beveled for engagement with the correspondingly beveled inner periphery of a split guide ring 30, having its outer periphery in engagement with the wall of the cylinder. The inner peripheral edge of the plate and the bearing face of the rib 29 of the plate'thus form the journals for rotation of the cutter head and inasmuch as they are disposed inwardly of the periphery thereof, they are protected from the cuttings, it being observed that only such movement would occur between the split ring 30 and the outer peripheral face of the plate as to permit expansion or contraction of the ring in assuming proper centering engagement with To insure a proper contact of the sets of bearing faces thus provided, in the assemblage of the cutter head, a spring is disposed between the bearing plate 10 and the shoulder of the bearing plug 26 formed at the juncture of its reduced threaded portion, said spring being preferably of the mushroom type and comprising an annulus 31 seated on the said shoulder and having curved fingers 32 engaging the plate 22. This Spring provides such frictional resistance to the threading movement of the plug 28 as to hold the bearing face thereof in engagement with the bearing edge of the plate 27 when said plate is rotatedto screw the plug into the cutter head block.

Referring now more particularly to Fig. 4, it is noted that some engine cylinders are open at both ends, or as shown in said figure a e provided with a combustion enlargement as at 38, in either instance the construction being such as to render the normal bearing and centering means in advance of the cutter head, inoperative in the latter portion of the cutting operation. To provide additional bearing means for the cutter blades under these conditions, whereby said blades are held for proper cutting movement to the end of the cylinder, an auxiliary cutter head block 34 is provided which is of substantially the same diameter as the main cutter head block 16 and which has a similar threaded bore therethrough, which is countersunk at 36 to receive the hub boss 23 of the main block upon removal of the bearing plate 22, whereby said blocks may fit to ether for the reception of fastening bolts 3 extended through the passages 25 of the main cutter head and through passages in the auxiliary head. The outer end of the auxiliary head is provided with a boss 38 adapted to receive thereon the plate 22 for engagement by the bolts 37 to clamp the cutter blades 21 in radial slots 39 similar to the slots 22 of the main cutter head, the bore 35 of the auxiliary head having an expanding plug 40 threaded therein with its end of conical shape to engage the blades. With the auxiliary cutter head attached, guide bars 41 are mounted in the blade slots 22 of the main cutter head and are engageable by the expanding plug 19 thereof, and have their outer ends rounded for slidin engagement with the bore of the cylinder whereby an inner. cutter head bearing is provided.

As shown more particularly in Fig. 7, the guide bars 41 may be provided with arcuate heads 42 at their outer ends which are faced with emery or other suitable abrading material whereby in their rotative engagement with the bore of the cylinder, said heads serve to finish the cutting surface made by the blades, as well as to guide the cutter head. I

In the use of the auxiliar cutter head, the bearing plug 28 is threa ed in its bore 35, and engages the late 27 in the usual manner, said plate an its centering ring 30 dropping from the head upon moving past the piston bearing portion of the cylinder.

When the blades 21' are disposed in the auxiliary cutter head, they are first adjusted by rotation of the plug 40, the guide bars 41 are then adjusted by rotation of the plug 19, and the entire structure is clamped together by tightening the bolts 37 to draw the plate 22 against the cutter blades 21 and to draw the auxiliary cutter head block 34 against the bearing bars 41.

To procure a proper centering of the various parts of the entire machine with respect to a cylinder in its initial application thereto for boring operation, the upper portion of the main cutter head is beveled in frusto-conical shape as at 43 to fit the correspondingly beveled inner eripheral face of a resilient split ring 44 W ich has its outer periphery engaged with and supported against the inner periphery of the'tubular supporting member 7. Thus, in the appli cation of the machine for cutting operation by the main cutter head, the split lead ring 30 is positioned in the mouth of the work cylinder 5, the cutter head and bearing plate 27 are seated thereon and the tubular ousing 7 positioned about the cutter head by engagement of the beveled'face of the ring 44 and the cutter head block. The

bolts 13 are then applied and" tightened toclamp the tubular member and bearing late 9 in this properly centered position, it being noted that upon starting the cutting movement, the cutter head moves away from the ring 44. e;

Heretofore it has been considered essential to provide cylindrical bearing faces between the cutter head and the supporting member, with consequent great expense of manufacture involved in the necessity for procuring an accurate fittingof said cylindrical bearing surfaces. I take advantags of the fact that the cutter head and support have need for centering engagement only in the initial positionin of the machine, to eliminate the expense involved in fitting such cylindrical faces by the provision of frusto-conical faces as described which provide an efiicient centering engagement only, as necessary, in the initial positioning. A considerable economy of manufacture and a greater ease of operation is thus effected. It will be observed that if desired the function of the split ring 44 may be discharged by an integral annular projection of the inner periphery of the support 7.

What is claimed is:

1. In a cylinder reboring machine, a supporting member engageable against the end of a cylinder, a cutter head, means connected with the supporting member for feeding the cutter head into the cylinder, means for centering the cutter head within the cylin der, a beveled peripheral face on the cutter head and bearing means projected inwardly from the supporting member for engaging the beveled face of the cutter head to center it with respect to the supporting member.

2. In a cylinder reboring machine, a tubular supporting member engageable against the end of a cylinder, a cutter head, means connected with the-supporting member for feeding the cutter head into the cylinder, means for centering the cutter head within the cylinder, a beveled peripheral face on the cutter head and a split ring having its outer periphery engaged with the periphery of the support and having its inner periphery beveled to engage the beveled face of the cutter head.

3. A cylinder reboring machine including a support adapted for engagement with the end of a cylinder, a feed shaft-carried by said support, a cutter head on the shaft, a'

non-rotating bearing member adapted to move within the cylinder and having an annular bearing surface of lesser major diameter than the cutter head, a reduced bearing extension on thecutter head journaled in said member, and a centering ring disposed about the bearmg member and slidably engageable with the wall of a cylinder.

4. A cylinder reboring machine includ- I ing a support, a feed shaft carried by the support, a cutter head on the shaft, a nonrotating bearing member adapted to move within the cylinder, means for centering the bearing. member in the cylinder, coacting bearing faces on the cutter head and bearing member disposed in a plane at right angles to the axes thereof, and coacting bearing faces "on the cutter head and bearing member preventing relative lateral movement thereof.

5. A cylinder reboring machine including I port, a cutter head on the shaft, a non-rotating bearing member adapted to move within the cylinder, and provided with an annular flat bearing face engaging the cutter head and with a central frusto-conical bearing face, and a bearing member carried by the cutter head and engaged with said frusto-conical bearing face andadjustable toward and away from the cutter head to coordinate such engagement with the engagement of the said flat bearing face and the cutter head.

6. A cylinder reboring machine including asupport,afeed shaft carried by the support a cutter head on the shaft, a bearing member adapted to move Within the cylinder, and provided with an annular fiat bearing face engaging the cutter head and with a central frusto-conieal bearing face, a bearing member threaded in the cutter head and engaged with said frusto-conical bearing face and a spring opposing threaded movement of the bearing member toward the cutter head.

' 7. A cylinder reboring machine including the combination with a support, a feed shaft carried by the support, and a main cutter head on the shaft provided with cutter blade securing means, of an extension cutter head adapted for connection with the main cutter head, and cylinder engaging guide members adapted for securement to the main cutter head by said cutter blade securing means.

8. A cylinder reboring machine including the combination With a support, a feed shaft carried by the support, a cutter head on the shaft having transverse cutter blade slots therein, and an expanding member in the cutter head and engageable with the blades, of an extension cutter head adapted for connection with the main cutter head, and cylinder engaging guide members insertible in I nection with the bearing means of the main cutter head.

10. A cylinder reboring machine including a support, a feed shaft carried thereby, a cutter head on the shaft, a boss on the cutter head, bearing means for the-main cutter head including a bearing plate engageable on said boss, an auxiliary cutter head having a countersunk portion for receiving said boss, a boss on the auxiliary cutter head adapted for engagement thereon of the hear-- ing member of said main cutter head bearing means, and cylinder engaging guide members adapted for securement to the main cutter head.

11. A cylinder reboring machine includinga support, a feed shaft carried thereby, a cutter head block having one end portion connected with the shaft and provided with radial cutter blade slots in its other end portion, said other end portion of the cutter head block being cut away to form a boss and to expose the outer sides of the slots, cutter blades in the slots, an annular plate disposed about the boss, means connecting the annular plate and cutter head block to clamp the blades in the slots, a bearing member threaded in the boss and a centering means for the cutter head including a member having ,beari'ng engagement with said bearing member.

12.-A cylinder reboring machine including a support, a feed shaft carried thereby, a cutter head block having one end portion connected with the shaft and provided with radial cutter blade slots in its other end portion, said other end portion of the cutter head block being cut away to form a boss and to expose theouter sides of the slots, cutter blades in the slots, an annular plate disposed about the boss, means connecting the annular plate and cutter head block to clamp the blades in the slots, a bearing member threaded in the boss and a centering means for the cutter head including a plate having bearing engagement with said annular plate and with said bearing member.

' In testimony whereof, I aflix my signature, in the presence of two Witnesses.

OSCAR W. NELSON.

Witnesses:

V. H. DAY, S. BEADLE. 

